*UPDATED, SEE BOTTOM OF POST*
I've owned my EDC3's for just over 5 months now, and I use them nearly every day. They are extremely comfortable, easy to drive, and possess a reasonably strong bass (unlike most BA IEMs). The flat response is difficult to enjoy at first if you're used to a more V-shaped sound, but over time I've come to greatly enjoy the level of nuance these babies provide to any kind of music. I can EQ a small bass bump to give things a bit more punch and they handle that with ease and no distortion even at high volume.
I listen to a very wide range of music, focused on metal/rock and extreme metal but also a lot of psychedelic trance, ambient and whatever else strikes my fancy. I use these for gaming and for listening to audio books in bed. For music with bass and speedy sounds, they deliver punch and clarity. With audio books or quieter music, the bass is not overblown nor are the treble frequencies shrilly harsh. The sound reproduction is always smooth and balanced, even when driven to the limit of amplification. Sound stage is reasonably open with good stereo, though obviously not quite to the level of over-ears.
The driver units are decently sound-isolating on their own, but not so much that if your music is off you can't hear some sound around you. With music on, at a good volume - you're in your own world. On the bus, using the foam tips, I can't hear anything but music. It's wonderful to not have to rely on heavy and loud music every morning for blessed isolation.
I use the RadSone ES100 as the primary DAC, amp, and EQ for these, but they work just fine from my Kindle or S9+ or whatever else I plug them into. I found the braided cable to be a little loose for my taste so I twisted them up tighter, but that made them stiff - that's my fault, just don't do as I did! Aside from that I am very happy with the cable. It doesn't tangle too much or get stuck on things. Pretty much what you want from a braided cable.
For the price, I can't think of anything negative with these. Perhaps you could find fault with the joint where the wires go into the drivers: it has a unique shape that makes it awkward to use custom cables with them. These are the most comfortable IEM's I've ever worn, and I find the fit to be solid. They never come loose and I can even let them hang from their ear loops when I need to talk someone, without worrying they'll flop off when I turn my head.
(NOTE: I also own the EDC. Compared to the EDC3, the EDC has boomy, overpowered bass that unpleasantly muddies the mid-range and flattened/reduced treble response. The EDC3 has crisp, full highs; encompassing, strong mids; and smooth, extensive bass. If all you care about is bass and more bass then the EDC3 is not for you.)
UPDATE: My EDC3's died a few months ago so I had to engage NuForce for warranty replacement. There were some communication issues as emails from support ended up being lost in spam filters, but otherwise I got a new, retail box set of IEMs in about 3 weeks.
I definitely recommend calling them, the response is MUCH faster. Being without them for a few weeks really tripped me out so I'll probably get a spare set soon.